DESCRIPTION (Verbatim from Applicant's Abstract): Electrical injury is one of the common traumas in the civilized countries. It is important to understand the mechanisms of electrical injury in order to develop efficient therapeutic techniques and management procedures for electrically injured patients. The current accepted mechanism involved in electrical injury is cell membrane electroporation resulting in leakage of ions and cellular contents out of the cells. Our hypothesis is that electro-coupled conformational damages in the membrane proteins, especially the voltage-dependent proteins may also play an important role in electrical injury. This is because approximately 40 percent of the cell membrane, byweight, consists of proteins functioning as ionic channels, transporters and signal receptors, which are often sensitive to the changes in the membrane potential. Therefore, these membrane proteins are vulnerable to an intensive electric field. In the last few years, we have systematically investigated the supramembrane potential shock induced functional changes in the voltage-dependent Na+ and K+ channels on the membrane of skeletal muscle fibers. We found that these shock field induced channel functional alteration was mainly not due to the Joule heating effects but most likely due to the field induced protein conformational changes in the channel gating system. To prove our hypothesis and reveal insight mechanisms involved in the electrical injury, we will continuously study the electroconformational damages in the membrane proteins. We will study the shock field induced changes in the Na+ channel gating currents to provide direct evidence of the proteins conformational changes. Based on our previous studies, we will further consider the skeletal muscle fiber as a system, instead of individual proteins, to investigate the intensive shock effects on the fiber electrical excitability and the muscle fiber excitationcontraction coupling process. These studies will lead to a comprehensive understanding of the underlying mechanisms involved in electrical injury.